Traps for yellowjacket wasps (Vespula species), are numerous. They take many shapes and configurations, but generally require an attractant within the trap to attract insects toward openings through which the insects enter. Insects become trapped within the devices and die by either drowning (in a water-filled trap) or by dehydration and starvation (in a non-water filled trap). The present invention is of the latter type.
A tube-shaped yellowjacket trap has been disclosed in U.S. Pat. No. 4,551,941 by Schneidmiller. The Schneidmiller trap is a cylindrical tube with two end caps. The top end cap is a perforated screen which allows air into the trap. The lower cap contains an attractant cup and entrance structure, through which insects pass to enter the trap. Once inside the lower section of the trap, insects seek escape through an inverted, perforated cone having a smaller opening toward the top of the trap. The insects move toward light entering the top and sides of the trap. Once insects have passed through the smaller aperture of the inverted cone, they become trapped in the uppermost section of the trap and later die of dehydration or starvation.
An improved, tube-shaped trap has more recently been disclosed by Schneidmiller in U.S. Pat. Nos. 5,557,880 and D372,513. The trap consists of a cylindrical tube having a closed upper end and an open lower end. The closed upper end of the tube has slots arranged radially around the top for airflow. A truncated cone with two open ends is arranged within the cylinder, such that the end having a smaller opening projects into the uppermost interior portion of the cylinder. The other end of the cone has a larger opening fitting against the inner circumference of the wall of the cylinder approximately at the open end of the cylinder; and a cap which attaches threadably to the open end of the cylinder, and which holds the cone in place within the cylinder.
A lure is placed in the cup. Airflow through the trap allows attractant to be dispersed, so that it may come into contact with the wasps in the vicinity of the trap, which are then lured into the trap through small holes in the bottom of the cap. Once inside the lower section of the trap, insects perceive the open top end of the inner cone as an escape route, since light projects from the outside of the trap and the top of the trap into the interior of the trap, and through the inner cone. Thus, insects move through the smaller hole at the top of the cone into the upper section of the trap, where they die of dehydration and/or starvation. Insects are removed by unscrewing the cap, removing the inner cone and pouring out the insect carcasses.
The Schneidmiller trap has several drawbacks. First, it cannot be placed on a table or other level surface. Also, this design does not allow for entry of insects from the side of the trap. Yellowjackets normally approach the trap from the sides, and have trouble finding their way into the trap. A significant percentage of insects approaching the trap cannot find the entrance into the trap to reach the attractant. The improved Schneidmiller trap is designed for better airflow through various holes in the sides and top of the trap. However, airflow through the trap directs attractant to these airflow holes and not specifically to the entrance holes, thus confusing the insects. Additionally, it is very difficult to empty the trap of dead insects, requiring that the user completely disassemble the trap in order to empty the upper chamber. The inner cone through which insects move into the upper chamber must be removed from the body of the trap to allow removal of insects. This is a clumsy operation and can result in wasp stings to the user, should there be live wasps remaining in the trap.
The present invention overcomes these problems and results in a far more effective trap, especially for yellowjacket wasps.